Power of Attorney is a big step.  First you need a full medical workup.  Occupational therapist do cognitive screening with a series of simple tests.  By having one of these periodicly you can map out a decline.  The mini mental the doctor uses is not much help. A mini- mental is they ask you 10 simple questions, including recall over a few minutes.  At the beginning of the test you tell them to remember 3 things- ball, typewriter, bill.  Then after several other questions they are asked to recall this.  They are also asked to write a simple sentence.  It is a first step in knowing there is a problem, but doesn’t really tell you what issues are failing.  The Occupational therapist exam they can actually tell you what problems they will encounter in their daily life, and give you ways to help them.  I was a visiting nurse for 9 years.  The visiting nurse service should have, physical therapist, occupational therapist, home health aides. nursing and a social worker.  talk to her physician about more extended workup.  hire a Elder Care Lawyer. Best of Luck